Air conditioner



H. F. LATHROP AIR CONDITIONER Jan. 30, 1962 2 Sheets-Sheet 1 Filed May9, 196,0

1| lllaldlhrdu nu INVENTOR.

HAROLD F. LATHROP ATTORN EY H. F. LATHROP AIR CONDITIONER Jan. 30, 19622 Sheeis-Sheet 2 Filed May 9, 1960 INVEN TOR.

HAROLD F. LATHROP ATTORNEY United States Patent 3,018,642 AIRCONDITIONER Harold F. Lathrop, Milan, Ill., assignor to American AirFilter Company, Inc, Louisville, Ky a corporation of Delaware Filed May9, 1960, Ser. No. 27,758 9 Claims. (Cl. 62427) This invention relates toa self-contained air conditioner particularly adapted to be employed forcooling or heating mobile enclosures such as military ground supporttrailers or vans, or other portable shelters.

The objects of the present invention include the provision of aself-contained air conditioner of the air cooled type which: may be usedto either cool or heat an enclosure; is relatively lightweight and hasits component parts arranged to provide a compact package facilitatingits transport; includes a compartmentalized construction to provide aseparate compartment for a refrigeration condenser and evaporatorrespectively; includes provision for diverting a part of the outside airadmitted into the condenser compartment to the evaporator compartmentwith means provided for regulating the proportion of outside air thusdiverted; and is structurally arranged to minimize short circuiting ofthe condenser compartment discharge air back to the condensercompartment air inlet.

Other objects and features of the invention will be ap preciated fromthe following description which is to be considered in connection withthe accompanying drawing illustrating the principles of the inventionincorporated in one embodiment by way of example and wherein:

FIGURE 1 is a partly broken isometric view of the air conditioner withcertain parts deleted for clarity;

IFIGURE 2 is an isometric view of the air conditioner mounted in anexterior wall of an enclosure to be conditioned, this view illustratingthe condenser compartment air inlet and air outlet covers in a positionfor cooling cycle operation;

FIGURE 3 is a partly broken elevational view of the exterior or rear ofthe air conditioner with the condenser compartment covers in a closedposition; and

FIGURE 4 is a partly diagrammatic vertical sectional View taken alongthe line 44 of FIGURE 3.

Referring to the drawing, the cabinet for the air conditioner is anupright generally rectangular casing formed by a pair of oppositesidewalls 2, a top wall 4, a bottom wall 6, a front or inner wall 8, anda rear or outer wall 10. The panels forming these cabinet walls arepreferably of a lightweight material such as aluminum which isfabricated and welded so that the casing portion of the cabinet whichprojects outside of the enclosure is watertight and adapted to be sealedfrom the outside environment when its associated covers are closed,while the inside portion includes removable front panels which permitaccess to the interior of the cabinet. A peripheral mounting flange 12which carries a gasket and extends around the top, bottom and side wallsadds strength and rigidity to the cabinet. When the cabinet is mountedin an opening in an exterior wall of an enclosure 14 (FIGURE 2), theinner or front portion of the cabinet projects into the enclosure andthe rear or outer portion of the cabinet projects outside of theenclosure.

The cabinet interior is divided by a horizontally disposed partition 16into two main compartments; a lower condenser compartment 18 and anupper evaporator compartment 20. This main partition 16 generally sealsthe upper and lower compartment from each other and is insulated tominimize heat transmission between the compartments.

A finned coil condenser 22 extends horizontally across the lowercompartment 18 to divide it into a lower portion which has suitablymounted therein a hermetic compressor 24, a liquid receiver 26 andcertain other refrigeration system elements, and an upper portioncontaining a pair of motor driven centrifugal fans 28 and an electricalcontrol box 30. Outside air for cooling the condenser during a coolingcycle operation is admitted into the condenser compartment through theoutside air inlet 32 located in the lower rear panel of the lowercompartment 18, with the major portion of the outside air admittedpassing through the condenser 22 normally and being discharged by thefans 28 through separate, horizontally spaced condenser air outlets 34which are spaced somewhat above the inlet 32.

An air inlet cover 36 in the form of a canopy having side walls whichretract into the cabinet when the cover is closed is hinged along itsupper edge so that the air inlet 32 is shielded from the top and sideswhen the cover is open as illustrated in FIGURES 2 and 4. To permitclosing the condenser air outlets 34 when the refrigeration system isnot being used, a cover 38 is provided. This cover is hinged along itslower edge and when swung to an open position as illustrated in FIGURE 2rests against the opened cover 36 in a position in which the condenserair outlets 34 are unobstructed.

The upper compartment 20 includes a finned coil refrigeration evaporator46 extending between the opposite cabinet side walls 2 and tilted orinclined forwardly so that its upper front edge is adjacent the frontwall 8 and its lower rear edge is spaced above the main partition 16. Abank of electric heating elements 42 is mounted adjacent the upper airflow face of the evaporator in tandem relation thereto. A pair ofcentrifugal fans 44 mounted in the upper rear corner of compartment 20are operable to induce air flow through the recirculation air inlet 46in the cabinet front wall 8, through the evaporator 40 and heatingelements 42, and to discharge conditioned air through the circulatingair outlet 48, also located in the cabinet front wall 8 but spacedupwardly from the recirculation air inlet.

The upper compartment 20 also contains a bafile or second partition 50spaced above the main partition 16 and underlying the evaporator 40.Baffle 50 has its front edge spaced rearwardly from the recirculationair inlet 46 and extends, on a level above the lower edge of the inlet-46 and between the opposite cabinet sidewalls 2, horizontally andrearwardly below the lower edge of the evapora-- tor 40, then upwardlyand rearwardly along the closed bottom surface of the evaporator, andthen rearwardly to the cabinet rearwall 10. The forward portion of thebaffle 50 forms with the upper surface of the'm-ain partition 16 and thecabinet side walls 2, a horizontal fresh air duct 52 which terminates atits front or discharge end in rearwardly spaced relation from thecabinet front wall 8. The inclined portion of the baffle 50 forms theupper wall of a transition section joining the horizontal fresh air ductto an air filter plenum designated 54 and having its upper wall formedby the rear horizontal portion of baffle 50. A vertically disposed airfilter 56 is suitably mounted in the filter plenum 54. The extent towhich the discharge end of the horizontal fresh air duct 52 is opened toadmit fresh air into the evaporator compartment 20 is controlled by afresh air damper 58 pivotally supported along its lower edge adjacentthe lower edge of the recirculation air inlet 46 in the cabinet frontwall 8. A lever 60 fixed to the damper 58 projects through a verticalslot in the cabinet front wall 8 and is employed to manually adjust thedamper setting between a forward extreme position (as shown in FIGURE 4)wherein the discharge end of the fresh air duct 52 is fully open and therecirculation air inlet 46 is partially blocked, and the opposite orrear extreme position (as shown in FIGURE 1) wherein the fresh air ductis fully closed and the recirculation air inlet is fully open.

The outside air flowing through the filter plenum 54, transition sectionand horizontal fresh air duct is induced by operation of the centrifugalfans 44 which draw fresh air from the lower portion of the lowercompartment 18 upwardly through a vertical fresh air duct 62 (FIGURES 3and 4) which has its lower open end 64 in communication with the spacebelow the condenser 22, and its open upper end 66 in communication withthe space on the upstream side of the air filter 56 in the filter plenum54. The vertical duct 62 extends upwardly along the rear or outer wallin the space behind the rear edge of the condenser 22 and centrallybetween the separate discharge plenums of the condenser air flow fans 28and thence through the rear central notch or opening in the mainpartition 16. Since the lower open end 64 of the vertical duct 62 isopen to the space below the condenser 22, the fresh air admitted theretois unheated air which has not been used to cool the condenser. Further,when the air conditioner is being used for heating, since the verticalair duct is immediately adjacent the outside wall, whatever fresh air isadmitted for ventilating flows into the open bottom end 64 withoutcontacting other elements in the condenser compartment and whilepermitting the condenser air outlet cover 38 to remain closed.

The baffie 50 not only serves as the upper wall of the horizontal freshair duct 56, but also serves as a drip tray for collecting condensatefrom the evaporator. The condensate which accumulates on the baffieupper surface flows into the open upper ends 68 of a pair of condensatedrainage tubes 70 which pass downwardly through the horizontal fresh airduct and main partition 16, and then rearwardly where they terminate inopen ends above the condenser air fan wheels 28 so that the condensatedropping from the open end of the tubes will be effectively atomized anddischarged along with the condenser air to the outside.

Access to the fresh air filter 54 is provided on the exterior of thecabinet through the filter access panel 72 suitably secured in flushrelation to the rear wall 10. The condenser air outlet cover 38 is ofsufficient height and width that when closed it also covers the filteraccess panel 72. Both covers 36 and 38 have peripheral gaskets 74 ontheir inner surfaces so that the exterior portion of the cabinet issealed when the covers are closed.

In the upper central part of the rear wall 10 an opening 76 is providedand is normally closed by a standard water tight female duct cover 78.Under circumstances of extreme low temperatures where the heat availablefrom the bank of electrical heaters is not sufficient for a rapid warmup, a portable heater may be connected by suitable duct work to theopening 76 to provide additional heat for the enclosure.

As has been noted previously and is apparent in FIG- URE 4, the rearedge of the condenser 22 is spaced from the rear wall 10 to accommodatethe vertical fresh air duct. Since this vertical fresh air duct 62 has awidth across the rear wall 10 limited by the spacing between thedischarge plenums of the condenser fans 34 which in turn are spacedinwardly from the side walls 2, space for the piping and wiring betweenthe refrigeration components in the lower compartment and uppercompartment is available in the vertical rear corners of cabinet. Suchpiping (not shown) extends upwardly along the rear corners of thecabinet and then forwardly between the side walls 2 and the adjacenthousing of the centrifugal fans 28, and then upwardly through partitions16 and 50 into the upper compartment. The triangular space between theupper closed edge of the evaporator 40 and the front wall 8 isconveniently available for mounting the thermal expansion and solenoidvalves used in connection with the refrigeration system.

Now considering the operation of the air conditioner in a cooling cycle,both covers 36 and 38 are opened to the position shown in FIGURES 2 and4. The refrigeration system and fans 28 and 44 are placed in operation,and the damper 58 is adjusted to a position permitting the admission ofa desired amount of fresh air. In FIG- URE 4, the passage of condenserair flow is indicated by the dotted arrows while fresh and recirculationair flow to the upper compartment is indicated by the solid line arrows.Assuming that the damper is adjusted to its extreme open position(partially blocking the recirculation air inlet 46 and correspondinglyincreasing the fresh air suction elfect of fans 44), the proportion ofrecirculated to fresh air may suitably be arranged to be, say, in theratio of 3 to 1. This fresh air is drawn upwardly by fans 44 through thevertical fresh air duct 62 and into the filter plenum 54 where, becauseof the relatively large sectional area across which the air filter 56extends, the velocity of the air flow is correspondingly reduced andfiltering performance thereby enhanced. The fresh air discharged fromthe horizontal fresh air duct mixes with the recirculating air admittedinto the upper compartment through recirculation air inlet 46 and thenpasses through the evaporator 40 past the de-energized electric heatingbank 42 and is discharged into the enclosure through recirculation airoutlet 48. Condensation which accumulates on the evaporator 40 and dripsonto the baffle 50, which as shown is inclined slightly downwardlytowards its rear, passes into the condensate drainage tubes 70 and isdischarged out of the condenser air flow outlets 34 along with condenserair flow. It is noted in connection with the operation of the airconditioner in a cooling cycle that the hot condenser air dischargedfrom outlets 34 tends to be thrown outwardly and then rise because ofits heat content and that the fresh air inlet 32, being shielded by thecover 36, admits outside air drawn into the open bottom of the cover.

When it is desired to operate the air conditioner in a heating cycle,the condenser air outlet cover 38 is closed and sealed and the condenserair fans 28 are not operated. The cover 36 is opened to the extentdeemed desirable in connection with the setting of the adjustable freshair damper 58. The refrigeration system is not operated, and the bank ofelectrical heating elements 42 are energized from an energy sourceexternal to the air conditioner and controlled by a step controller inaccordance with conventional practice.

The invention claimed is:

1. In an air conditioner assembly: an upright rectangular cabinetadapted to be sealably mounted in an exterior wall of a space to beconditioned; a first partition extending horizontally across theinterior of said cabinet to divide said cabinet into an uppercompartment and a lower compartment; a recirculation air inlet in theinner wall of said upper compartment adjacent the lower part thereof; aconditioned air outlet in the upper part of said upper compartment; heatexchange means extending across the upper compartment interior in thepath of air flow therethrough; first blower means in said uppercompartment for inducing said air flow through said heat exchange means;a second partition in the upper compartment having its inner edge spacedfrom said recirculation air inlet and extending horizontally andrearwardly in spaced relation above said first partition to formtherebetween an air duct in communication at its rear end with an airfilter plenum; a damper in said upper compartment disposed between thefront end of said air duct and said recirculation air inlet, said damperbeing pivotally supported along its lower edge and disposed forselective positioning between one extreme position closing said frontend of said air duct, and an opposite extreme position opening saidfront end and partially closing off said recirculation air inlet; anoutdoor air inlet in the lower part of the outer wall of said lowercompartment; an air outlet in the outer wall of said lower compartmentand spaced upwardly from said outdoor air inlet; a refrigerationcondenser extending horizontally across said lower compartment betweensaid lower compartment air inlet and air outlet and having its rear edgespaced from said outer wall to define a space therebetween; secondblower means in said lower compartment adapted to induce air flowthrough said lower compartment; a vertical air duct having an openbottom end in communication with the space in said lower compartmentbelow said condenser and extending upwardly in the space defined betweensaid condenser and said outer wall and through said first partition forcommunication at its open top end with said filter plenum.

2. In an air conditioner assembly: an upright rectangular cabinetadapted to be mounted in sealed relationship in an exterior wall of aspace to be conditioned; a first partition extending horizontally acrossthe interior of said cabinet to divide said cabinet into an uppercompartment and a lower compartment; an air inlet and an air outlet inthe upper compartment in communication with said space to be conditionedand blower means between said air inlet and air outlet for inducing theflow of air therethrough; heat exchange means including a refrigerationevaporator extending across said upper compartment interior andtransverse to the air flow therethrough, said evapoartor being inclinedforwardly with its upper forward corner adjacent the inner wall of saidupper compartment and its lower rearward corner spaced above said firstpartition; a second partition having its forward edge spaced rearwardlyof said upper compartment air inlet and extending horizontally andrearwardly below said lower edge of said condenser and above said firstpartition to define a horizontal fresh air duct with said firstpartition with the forward end of said horizontal duct being open andspaced rearwardly from said upper compartment air inlet, said secondpartition extending upwardly and then rearwardly along the lower edge ofsaid evaporator to define the upper wall of an air filter plenum ofsubstantially greater cross sectional area than the cross sectional areaof said horizontal fresh air duct; damper means disposed between saidopen forward end and said upper compartment air inlet, said damper meansbeing operable to vary the proportions of air drawn from said space andfrom said duct into said upper compartment; an outdoor air inlet and anupwardly spaced condenser air outlet in the outer wall of said lowercompartment; a refrigeration condenser extending across said lowercompartment between said lower compartment air inlet and outlet andhaving its rear edge spaced from said outer wall; second blower meansfor inducing air flow through said lower compartment; and, a verticalfresh air duct having its lower end in communication with the space insaid lower compartment below said condenser and its upper end incommunication with said filter plenum, said vertical fresh air ductextending up wardly through the space defined between said condenserrear edge and said outer wall of lower compartment.

3. In an air conditioner assembly as specified in claim 2 including:condensate drainage means in the form of tube means having condensateinlet means in communication with the upper surface of said secondpartition and extending downwardly through said second and said firstpartitions with condensate outlet means in communication with thedownstream side of said second blower means.

4. In an air conditioner assembly as specified in claim 2 including:cover means for said outdoor air inlet comprising a canopy-like memberrotatably mounted along its upper edge adjacent the upper edge of saidoutdoor air inlet, and operable to an open position wherein one wall ofsaid member projects outwardly between said outdoor air inlet and saidcondenser air outlet, and cover means for said condenser air outletoperable independently of said outdoor air inlet cover means and havingits lower edge pivotally mounted along an axis above the upper edge ofsaid canopy cover, whereby said outlet cover means may be swungoutwardly and downwardly to an open position permitting air dischargefrom said condenser air outlet directly outwardly.

5. In an air conditioner assembly as specified in claim 4 including:said upper compartment includes means defining a filter access openingin its rear wall between the rear edges of said second and firstpartition; panel means for closing said opening; and said condenser airoutlet cover means includes an extended portion adapted to encompasssaid panel means when said outlet cover means is in a closed position.

6. In an air conditioner assembly as specified in claim 5 including:means defining a normally closed auxiliary air supply opening in saidupper compartment for placing the space on the downstream side of saidheat exchange means in said upper compartment in communication with asource of auxiliary air.

7. In a self-contained air conditioner assembly: a cabinet adapted to bemounted in an exterior Wall of a space to be conditioned and havingfirst horizontal partition means dividing said cabinet into an upper andlower compartment, said upper compartment having a recirculation airinlet and circulating air outlet in the interior wall of said cabinetwith circulating air blower means disposed therebetween for inducing airflow through said upper compartment, and said lower compartment havingan outside air inlet and an upwardly spaced condenser cooling air outletin the exterior wall of said cabinet with condenser cooling air blowermeans therebetween for inducing air flow through said lower compartment;a refrigeration evaporator extending across the interior of said uppercompartment between said recirculation air inlet and said circulatingair outlet; a refrigeration condenser extending across the interior ofsaid lower compartment between said outside air inlet and said condensercooling air outlet; cover means for said outside air inlet operable toan open position in which a wall of said cover means projects outwardlybetween said outside air inlet and said condenser cooling air outlet forpreventing short circuiting of air between said outlet and said inlet; afresh air duct in said cabinet having an open bottom end adjacent saidoutside air inlet and extending vertically upwardly and forwardly withan open forward end spaced rearwardly from said recirculation air inlet;and damper means for controlling the admission of outside air to saidupper compartment, said damper means being diposed between said outsideair duct forward end and said recirculation air inlet and operablebetween one extreme position closing said forward end, and an oppositeextreme position opening said forward end and blocking a portion of saidrecirculation air inlet.

8. In a selfcontained air conditioner assembly: an upright cabinetincluding an upper compartment having an air inlet and an air outlet incommunication with the space to be conditioned and containing blowermeans therein for inducing a first air fiow through heat exchange meansdisposed between said inlet and outlet, and including a separate lowercompartment having an air inlet and an air outlet in communication withthe exterior of the space to be conditioned and containing blower meansfor inducing a second air flow through a refrigeration condenserdisposed between said lower compartment air inlet and air outlet; afresh air duct including a vertical portion having an open bottom endadjacent the air inlet of said lower compartment and an open top end incommunication with an air filter plenum in said upper compartment, andincluding a horizontal portion extending forwardly from said filterplenum in underlying relation to said heat exchange means and having aforwardly open end spaced rearwardly from said upper compartment airinlet; and damper means disposed between said open forward end of saidhorizontal portion and said upper compartment air inlet, said dampermeans being operable to selective positions between one extreme positionclosing said forward end, and an opposite extreme position opening saidforward end and blocking a portion of said upper compartment air inlet.

9. In an air conditioner assembly as specified in claim 8 wherein: therear edge of said condenser is spaced inwardly from the outer wall ofsaid lower compartment to define a space therebetween to accommodatesaid vertical portion of said fresh air duct; said lower compartmentblower means includes a pair of laterally spaced centrifugal fansadapted to discharge condenser cooling air through correspondinglylaterally spaced outlets; and said vertical fresh air duct extendsupwardly between said centrifugal fan outlet plenums.

References Cited in the file of this patent UNITED STATES PATENTS2,737,788 Buttner Mar. 15, 1956

